The present invention relates to a copying apparatus wherein it is possible to select a synchronized exposure mode or a stationary exposure mode.
In some copying apparatuses, it is possible to select a synchronized exposure mode or a stationary exposure mode.
Stationary exposure is an exposure method wherein a document is stationary and its image information is read by a moving optical system.
Synchronized exposure, on the other hand, is an exposure method wherein exposure is made by a stationary optical system with a document and a photoreceptor both moving synchronously.
In the case of the stationary exposure copying apparatus therefore, an automatic document feeder (ADF device) is popularly used as a document feeding means.
In the automatic document feeder, the document sheets stacked on a document-stacker are fed, sheet by sheet, onto a platen glass, and a document sheet on the platen glass is ejected, after exposure, onto an ejection tray located outside of the apparatus.
In FIG. 5A, the document feeding device 3 mounted on the platen glass of the main body 2 of the copying apparatus functions as an ADF device and in this case, a copy-handling means 1A, usually called a sorter, is frequently used.
On the sorter 1A, there are provided a plurality of ejection trays 5A-5D on each of which the finished copies are stacked sheet by sheet.
In a copying apparatus using a synchronized exposure, on the other hand, an automatic document feeding device of a recycling type (RDH device or Recirculating Document Handler) is popularly used as a document feeding device 3.
In the RDH device, the documents stacked on the document stacker are fed onto a platen glass of the copying apparatus sheet by sheet, and each of the documents on the platen glass, after exposure, is fed back to the document stacker again so that it may be fed repeatedly.
In this case, the copy-handling means 1B, usually called a finisher, is used.
In the finisher 1B, 40 is an ejection tray having a function similar to the sorter 1A, and on the intermediate tray 43, processing units 45 for various processes such as punching, stapling and others are provided. Processed copies are ejected onto the ejection tray 46.
In a copying apparatus wherein it is possible to select either a synchronized exposure mode or a stationary exposure mode, therefore, when an ADF mode is selected, the sorter 1A is used as a copy-handling means, while, when an RDH mode is selected, finisher 1B is used as a copy-handling means. FIG. 6 shows an example of an apparatus wherein the finisher 1B and the sorter 1A are connected in series to be used selectively.
When a synchronized exposure is made in a copying apparatus capable of performing a synchronized exposure and a stationary exposure selectively, it is common that the processing units 45 are used for various processes such as punching, stapling and others.
When considering the aforesaid processes, therefore, the time required for copying using synchronized exposure is longer than that using stationary exposure when plural sets of copies are made from a document.
In the case when a single set of copies is to be made from a document, on the other hand, the time required for copying using the synchronized exposure mode is shorter than that using the stationary exposure mode, even if the processes mentioned above are taken into consideration.
For example, when a user selects a stationary exposure mode (ADF mode) for only one set of copies, it is preferable that the ADF mode be changed automatically to the synchronized exposure mode (RDH mode) which provides the benefit of shorter copying time.
However, conventional copying apparatus of this kind have not been provided with a function that changes the ADF mode automatically to the RDH mode based on the number of sets of copies to be made.
The aforesaid points are reflected in the present invention and it provides a copying apparatus wherein when the stationary exposure mode is selected it may be changed automatically to the synchronized exposure mode when making only one set of copies, thereby reducing the copying time regardless of the exposure mode selected.